Image sensors widely employed in digital cameras function to convert optical signals into electrical signals. This conversion process may occur in pixels of a complementary metal oxide semiconductor (CMOS) image sensor (CIS), each pixel including a photodiode and a read circuit. An image may be obtained by generating charges from light absorbed into the photodiode and converting those charges into voltage and current. During this procedure, since information about brightness may be identified from an image, color filters may be used to obtain color information about the image. To display hue, three distinct colors may be needed.
An image sensor for implementing a color image may include color filters over pixels (photosensitive devices) generating and accumulating photoelectrons in response to externally incident light. The color filters may include three components, for example, red, green, and blue filters, or yellow, magenta, and cyan filters.
If there are many pixels integrated in an image sensor for the purpose of obtaining a high-quality image, sensitivity may be reduced and crosstalk increased in the image sensor because of a smaller pixel size.
Crosstalk is an effect of changing the original spectrum characteristics and deteriorating color reproductibility because of interference between a color signal from one pixel and a color signal from another pixel.
From this reason, a color correction system may be employed to repair problems with degradation of sensitivity and increases in crosstalk in an image sensor. However, color correction systems may cause an increase in noise, decreasing a signal-to-noise ratio (SNR) or a rate of color reproduction.